Smartwatches are facing what looks to be an ever-shakier future with Fitbit acquiring Pebble and Motorola opting to miss the launch of Android Wear 2.0. With Android Wear delayed in order to make sure it’s actually shippable, Google is continuing to release more developer previews. With DP4 today, Wear adds one-click Google Sign-in and authentication, in-app billing, and more.

The latest developer preview of Android Wear continues work on making the watch completely independent from the phone. Thanks to seamless authentication, users can log into watch apps and services from an Android or iOS device with the OAuth API for Android Wear.

With Wear devices featuring an on-device Play Store to browse and download, users can now authorize in-app purchases using a 4-digit Google Account PIN. Google points to this as a possible monetization strategy to make developing more attractive.

Additionally, DP4 is adding support for Wear 1.0 apps that have yet to be updated and are still packaged with a corresponding full phone app. This was one concern that many developers had with previous Android Wear 2.0 previews, as we highlighted a couple months ago.

Other UX tweaks include the return of swipe-to-dismiss currently found in Wear 1.0. Activities now automatically support the swipe, with a hardware button no longer being used to go back. Another enhancement to peeking behavior will allow users to take action without scrolling all the way to the top or bottom of a list. Additionally, burn-in protection will help ensure that complications in always-on mode do not damage the display.

There will be a fifth developer preview following this one, with Wear 2.0 still only available on the Huawei Watch and the LG Watch Urbane 2nd Edition.